MITCHELL, Sir ANDREW (1757–1806), admiral, second son of Charles Mitchell of Baldridge, near Dunfermline in Fife, born in 1757, was educated at the high school, Edinburgh. He entered the navy in 1771 on board the Deal Castle. After serving in different ships on the home station, in 1776 he went out to the East Indies in the Ripon with Sir Edward Vernon [q. v.], by whom he was promoted to be lieutenant of the Coventry frigate, 11 Oct. 1777, and to be captain, also of the Coventry, after the skirmish off Pondicherry on 10 Aug. 1778. His post rank was confirmed by the admiralty to 25 Oct. 1778. Mitchell continued in the Coventry after Sir Edward Hughes [q. v.] took command of the station; and on 12 Aug. 1782 fought a severe but indecisive action with the French 40-gun frigate Bellona off Friar's Hood in Ceylon. In September Hughes appointed him to the Sultan, in which he took part in the fight off Cuddalore on 20 June 1783. After the peace Mitchell remained on the station as commodore of a small squadron (Beatson, Naval and Mil. Memoirs, vi. 360), with his broad pennant in the Defence. He returned to England in 1786, having acquired in ten years' service a very considerable sum, which was lost by the bankruptcy of his agent. In the armament of 1790 he commanded the Asia, which was paid off on the settlement of the dispute; and in February 1795 he was appointed to the Impregnable in the Channel fleet. From her on 1 June 1795 he was promoted to the rank of rear-admiral.

On 14 Feb. 1799 he was advanced to be vice-admiral, and in April was appointed to a command in the North Sea under Lord Duncan. In August he had charge of the transports for the expedition to Holland; and though Duncan himself convoyed them across and superintended the disembarkation of the troops, he left the further operations to Mitchell, who on 30 Aug. received the surrender of the Dutch ships, consequent on the mutiny of the Dutch seamen, who refused to fight against the allies of the Prince of Orange. Their brethren on shore took a different view of the position, and in conjunction with the French repulsed the English and Russian army; so that the Duke of York, who was in command, was compelled to ask for an armistice, on the basis of an immediate evacuation of Holland. Mitchell, who, with a squadron of small vessels, had made himself master of the Zuyder Zee, was bound by the same treaty, and withdrew his ships; but neither he nor Sir Ralph Abercromby, who had commanded the army at its first landing, was blamed for the ignominious termination of the campaign; the thanks of parliament were given to both, as well as to the officers and men; and Mitchell was nominated a K.B., 9 Jan. 1800. The city of London, too, presented him with a sword of the value of one hundred guineas.

During 1800 and 1801 he commanded in the Channel fleet, under Lord St. Vincent and Admiral Cornwallis, and in November 1801 was detached with a squadron to the coast of Ireland and to Bantry Bay. In December, on some of the ships being ordered to sail for the West Indies, a mutiny broke out, especially on board the Téméraire, the flagship of Rear-admiral George Campbell. The mutiny was suppressed, and some twenty of the ringleaders, having been made prisoners, were brought round to Spithead, where they were tried by a court-martial, of which Mitchell was president. The greater number of them were found guilty and were executed (the minutes of the court-martial were published, 8vo, 1802). In the spring of 1802 Mitchell was appointed commander-in-chief on the North American station. On 9 Nov. 1805 he was promoted to be admiral; after a short illness he died at Bermuda on 26 Feb. 1806, and was buried there with military honours. He was twice married, having by his first wife three sons, Charles, Nathaniel, and Andrew (Marshall, Roy. Nav. Biog. vii. 325, viii. 380, and ix. 215), who all died captains in the navy. By his second wife he had a daughter. His portrait by Bowyer has been engraved (Catalogue of the Naval Exhibition, 1891).